Diurnal variations of mouse plasma and hepatic bile acid concentrations as well as expression of biosynthetic enzymes and transporters

Autor: Grace L. Guo, Curtis D. Klaassen, Yu-Kun Jennifer Zhang
Jazyk: angličtina
Rok vydání: 2011
Předmět:
Male
Anatomy and Physiology
Mouse
Receptors
Cytoplasmic and Nuclear
lcsh:Medicine
Biochemistry
Mice
0302 clinical medicine
Gastrointestinal Cancers
Enterohepatic Circulation
Gastrointestinal Infections
lcsh:Science
Enterohepatic circulation
0303 health sciences
Multidisciplinary
Membrane Glycoproteins
Bile acid
Animal Models
Lipids
Ursodeoxycholic acid
Circadian Rhythm
Sterols
Liver
030220 oncology & carcinogenesis
Medicine
Small Intestine
Biliary Disorders
medicine.drug
Research Article
Signal Transduction
medicine.medical_specialty
medicine.drug_class
Dietary lipid
Cholestyramine Resin
education
Gastroenterology and Hepatology
Biology
Gene Expression Regulation
Enzymologic
Bile Acids and Salts
03 medical and health sciences
Model Organisms
Internal medicine
medicine
Animals
Circadian rhythm
RNA
Messenger
030304 developmental biology
Cholestyramine
lcsh:R
Metabolism
Lipid Metabolism
Mice
Inbred C57BL
Endocrinology
Farnesoid X receptor
lcsh:Q
Physiological Processes
Carrier Proteins
Transcriptome
Chronobiology
Gene Deletion
Zdroj: PLoS ONE, Vol 6, Iss 2, p e16683 (2011)
PLoS ONE
ISSN: 1932-6203
Popis: Background Diurnal fluctuation of bile acid (BA) concentrations in the enterohepatic system of mammals has been known for a long time. Recently, BAs have been recognized as signaling molecules beyond their well-established roles in dietary lipid absorption and cholesterol homeostasis. Methods and Results The current study depicted diurnal variations of individual BAs detected by ultra-performance liquid chromatography/mass spectrometry (UPLC/MS) in serum and livers collected from C57BL/6 mice fed a regular chow or a chow containing cholestyramine (resin). Circadian rhythms of mRNA of vital BA-related nuclear receptors, enzymes, and transporters in livers and ilea were determined in control- and resin-fed mice, as well as in farnesoid X receptor (FXR) null mice. The circadian profiles of BAs showed enhanced bacterial dehydroxylation during the fasting phase and efficient hepatic reconjugation of BAs in the fed phase. The resin removed more than 90% of BAs with β-hydroxy groups, such as muricholic acids and ursodeoxycholic acid, from serum and livers, but did not exert as significant influence on CA and CDCA in both compartments. Both resin-fed and FXR-null mouse models indicate that BAs regulate their own biosynthesis through the FXR-regulated ileal fibroblast growth factor 15. BA flux also influences the daily mRNA levels of multiple BA transporters. Conclusion BA concentration and composition exhibit circadian variations in mouse liver and serum, which influences the circadian rhythms of BA metabolizing genes in liver and ileum. The diurnal variations of BAs appear to serve as a signal that coordinates daily nutrient metabolism in mammals.
Databáze: OpenAIRE
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